This invention relates to a multi-protocol switching system that contains various types of interfaces, such as ATM (asynchronous transfer mode) and Ethernet, and processes the higher protocol, an line interface that is provided for the system and serves as an interface to line, and a multi-protocol processing device that is included in the trunk section of the system.
In conventional multi-protocol switching systems, it has been necessary to mount multiple kinds of protocol processing devices for processing the respective protocols of line interfaces at the trunk section of the system according to the kinds of line interface.
In general, in multi-protocol switching system, the traffic of data transfer between line interfaces is more than the traffic to or from the protocol processing device. Namely, the usage rate of a bus between protocol processing device and switch is lower than the usage rate between line interface and switch. Therefore, when multiple protocol processing devices are mounted on a multi-protocol switching system, there must exist ports with a low usage rate connected to multiple protocol processing devices. Thus, the resource of switch cannot be used efficiently.
Also, in multi-protocol switching system, besides the function to repeat data from line interface to line interface, the routing destination determination function to determine a destination line interface is required. Also, required is a function that a central processing device manages the congestion state of multi-protocol switching system or the processing state of centralized processing section, informing these states of each line interface, thereby changing dynamically into a centralized processing section assigned to repeating. These three functions cannot be realized by only information of line interface to input data. To realize these functions, the centralized processing using information from all line interfaces is required
Meanwhile, the line interface includes various types of line interfaces, such as a line interface for connection-oriented communication like ATM and a line interface for connectionless communication like IP (Internet protocol). Taking the case of the above routing processing, in conducting the centralized processing both the routing processing or connection-oriented communication and the routing processing of connectionless communication, the processing load becomes heavy. Also, when trying to increase the kind of line interface, it is expected that part to conduct the centralized processing mentioned above is subject to a heavy load and thereby it is difficult to add the kind or number of line interface.
Furthermore, in transferring data from line interface to centralized operation section, when the line interface and centralized operation section are connected through a conventional bus, the transfer capability to the increase of line interface becomes insufficient.
Accordingly, it is an object of the invention to provide a multi-protocol switching system that offers a high usage rate of port to which a protocol processing device is connected.
According to the invention, a multi-protocol switching system, comprises:
a plurality of line interfaces that comprise an input section for inputting data from a network, a forwarding table, a determination section for determining a destination of the input data based on the content of a header of the input data and the content of the forwarding table, a packet generating section for generating a packet, when the destination determined by the determination section is a protocol processor, by adding a processor identifier of the protocol processor as the destination in a multi-protocol processing device and a port number to which the multi-protocol processing device equipped with the protocol processor is connected to the input data, or when the destination determined by the determination section is a line interface, by adding a port number to which the line interface as the destination is connected to the input data, and an output section for outputting the packet through the port to a switch:
the switch for forwarding the packet to the port having the port number included in the packet; and
the one or more multi-protocol processing devices that comprise a switch interface for inputting/outputting the packet to/from the switch through the port, a plurality of protocol processors which are provided corresponding to the kind of protocol and each of which has a processor identifier defined in the multi-protocol processing device, and a processor selecting section for outputting the packet input through the switch interface to the protocol processor having the processor identifier included in the packet;
wherein a protocol handled by one or the plurality of line interfaces is different from a protocol handled by another of the plurality of line interfaces.
According to another aspect of the invention, a line interface, comprises:
an input section for inputting data from a network;
a forwarding table:
a determination section for determining a destination of the input data based on the content of a header of the input data and the content of the forwarding table;
a packet generating section for generating a packet, when the destination determined by the determination section is a protocol processor, by adding a processor identifier of the protocol processor as the destination in a multi-protocol processing device and a port number to which the multi-protocol processing device equipped with the protocol processor is connected to the input data, or when the destination determined by the determination section is a line interface, by adding a port number to which the line interface as the destination is connected to the input data; and
an output section for outputting the packet through the port to a switch.
According to another aspect of the invention, a multi-protocol processing device, comprises:
a switch interface for inputting/outputting a packet to/from a switch through a port;
a plurality of protocol processors which are, provided corresponding to the kind of protocol and each of which has a processor identifier defined in the multi-protocol processing device; and
a processor selecting section for outputting the packet input through the switch interface to a protocol processor having the processor identifier included in the packet.
In this invention, the multi-protocol switching system for containing various types of interfaces, such as ATM (asynchronous transfer mode) and Ethernet, and processing the higher protocol is characterized in that it is provided with a multi-protocol processing device to handle multiple kinds of protocols at the trunk section of switch so an to maximize the usage rate of the switch, and that the multi-protocol processing device has a function for performing the distributed processing to each protocol. Also, the multi-protocol switching system of the invention is characterized in conducting the distribution of processing to each protocol by self-routing.